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/*
Copyright 2014 The Kubernetes Authors All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package unversioned
import (
"bytes"
"fmt"
"io"
"io/ioutil"
"mime"
"net/http"
"net/url"
"path"
"strconv"
"strings"
"time"
"github.com/golang/glog"
"k8s.io/kubernetes/pkg/api/errors"
"k8s.io/kubernetes/pkg/api/unversioned"
"k8s.io/kubernetes/pkg/api/v1"
"k8s.io/kubernetes/pkg/api/validation"
"k8s.io/kubernetes/pkg/client/metrics"
"k8s.io/kubernetes/pkg/conversion/queryparams"
"k8s.io/kubernetes/pkg/fields"
"k8s.io/kubernetes/pkg/labels"
"k8s.io/kubernetes/pkg/runtime"
"k8s.io/kubernetes/pkg/util"
"k8s.io/kubernetes/pkg/util/sets"
"k8s.io/kubernetes/pkg/watch"
watchjson "k8s.io/kubernetes/pkg/watch/json"
)
// specialParams lists parameters that are handled specially and which users of Request
// are therefore not allowed to set manually.
var specialParams = sets.NewString("timeout")
func init() {
metrics.Register()
}
// HTTPClient is an interface for testing a request object.
type HTTPClient interface {
Do(req *http.Request) (*http.Response, error)
}
// ResponseWrapper is an interface for getting a response.
// The response may be either accessed as a raw data (the whole output is put into memory) or as a stream.
type ResponseWrapper interface {
DoRaw() ([]byte, error)
Stream() (io.ReadCloser, error)
}
// RequestConstructionError is returned when there's an error assembling a request.
type RequestConstructionError struct {
Err error
}
// Error returns a textual description of 'r'.
func (r *RequestConstructionError) Error() string {
return fmt.Sprintf("request construction error: '%v'", r.Err)
}
// Request allows for building up a request to a server in a chained fashion.
// Any errors are stored until the end of your call, so you only have to
// check once.
type Request struct {
// required
client HTTPClient
verb string
baseURL *url.URL
codec runtime.Codec
// generic components accessible via method setters
path string
subpath string
params url.Values
headers http.Header
// structural elements of the request that are part of the Kubernetes API conventions
namespace string
namespaceSet bool
resource string
resourceName string
subresource string
selector labels.Selector
timeout time.Duration
groupVersion unversioned.GroupVersion
// output
err error
body io.Reader
// The constructed request and the response
req *http.Request
resp *http.Response
backoffMgr BackoffManager
}
// NewRequest creates a new request helper object for accessing runtime.Objects on a server.
func NewRequest(client HTTPClient, verb string, baseURL *url.URL, groupVersion unversioned.GroupVersion, codec runtime.Codec, backoff BackoffManager) *Request {
if backoff == nil {
glog.V(2).Infof("Not implementing request backoff strategy.")
backoff = &NoBackoff{}
}
metrics.Register()
return &Request{
client: client,
verb: verb,
baseURL: baseURL,
path: baseURL.Path,
groupVersion: groupVersion,
codec: codec,
backoffMgr: backoff,
}
}
// Prefix adds segments to the relative beginning to the request path. These
// items will be placed before the optional Namespace, Resource, or Name sections.
// Setting AbsPath will clear any previously set Prefix segments
func (r *Request) Prefix(segments ...string) *Request {
if r.err != nil {
return r
}
r.path = path.Join(r.path, path.Join(segments...))
return r
}
// Suffix appends segments to the end of the path. These items will be placed after the prefix and optional
// Namespace, Resource, or Name sections.
func (r *Request) Suffix(segments ...string) *Request {
if r.err != nil {
return r
}
r.subpath = path.Join(r.subpath, path.Join(segments...))
return r
}
// Resource sets the resource to access (<resource>/[ns/<namespace>/]<name>)
func (r *Request) Resource(resource string) *Request {
if r.err != nil {
return r
}
if len(r.resource) != 0 {
r.err = fmt.Errorf("resource already set to %q, cannot change to %q", r.resource, resource)
return r
}
if ok, msg := validation.IsValidPathSegmentName(resource); !ok {
r.err = fmt.Errorf("invalid resource %q: %s", resource, msg)
return r
}
r.resource = resource
return r
}
// SubResource sets a sub-resource path which can be multiple segments segment after the resource
// name but before the suffix.
func (r *Request) SubResource(subresources ...string) *Request {
if r.err != nil {
return r
}
subresource := path.Join(subresources...)
if len(r.subresource) != 0 {
r.err = fmt.Errorf("subresource already set to %q, cannot change to %q", r.resource, subresource)
return r
}
for _, s := range subresources {
if ok, msg := validation.IsValidPathSegmentName(s); !ok {
r.err = fmt.Errorf("invalid subresource %q: %s", s, msg)
return r
}
}
r.subresource = subresource
return r
}
// Name sets the name of a resource to access (<resource>/[ns/<namespace>/]<name>)
func (r *Request) Name(resourceName string) *Request {
if r.err != nil {
return r
}
if len(resourceName) == 0 {
r.err = fmt.Errorf("resource name may not be empty")
return r
}
if len(r.resourceName) != 0 {
r.err = fmt.Errorf("resource name already set to %q, cannot change to %q", r.resourceName, resourceName)
return r
}
if ok, msg := validation.IsValidPathSegmentName(resourceName); !ok {
r.err = fmt.Errorf("invalid resource name %q: %s", resourceName, msg)
return r
}
r.resourceName = resourceName
return r
}
// Namespace applies the namespace scope to a request (<resource>/[ns/<namespace>/]<name>)
func (r *Request) Namespace(namespace string) *Request {
if r.err != nil {
return r
}
if r.namespaceSet {
r.err = fmt.Errorf("namespace already set to %q, cannot change to %q", r.namespace, namespace)
return r
}
if ok, msg := validation.IsValidPathSegmentName(namespace); !ok {
r.err = fmt.Errorf("invalid namespace %q: %s", namespace, msg)
return r
}
r.namespaceSet = true
r.namespace = namespace
return r
}
// NamespaceIfScoped is a convenience function to set a namespace if scoped is true
func (r *Request) NamespaceIfScoped(namespace string, scoped bool) *Request {
if scoped {
return r.Namespace(namespace)
}
return r
}
// AbsPath overwrites an existing path with the segments provided. Trailing slashes are preserved
// when a single segment is passed.
func (r *Request) AbsPath(segments ...string) *Request {
if r.err != nil {
return r
}
if len(segments) == 1 {
// preserve any trailing slashes for legacy behavior
r.path = segments[0]
} else {
r.path = path.Join(segments...)
}
return r
}
// RequestURI overwrites existing path and parameters with the value of the provided server relative
// URI. Some parameters (those in specialParameters) cannot be overwritten.
func (r *Request) RequestURI(uri string) *Request {
if r.err != nil {
return r
}
locator, err := url.Parse(uri)
if err != nil {
r.err = err
return r
}
r.path = locator.Path
if len(locator.Query()) > 0 {
if r.params == nil {
r.params = make(url.Values)
}
for k, v := range locator.Query() {
r.params[k] = v
}
}
return r
}
const (
// A constant that clients can use to refer in a field selector to the object name field.
// Will be automatically emitted as the correct name for the API version.
NodeUnschedulable = "spec.unschedulable"
ObjectNameField = "metadata.name"
PodHost = "spec.nodeName"
PodStatus = "status.phase"
SecretType = "type"
EventReason = "reason"
EventSource = "source"
EventType = "type"
EventInvolvedKind = "involvedObject.kind"
EventInvolvedNamespace = "involvedObject.namespace"
EventInvolvedName = "involvedObject.name"
EventInvolvedUID = "involvedObject.uid"
EventInvolvedAPIVersion = "involvedObject.apiVersion"
EventInvolvedResourceVersion = "involvedObject.resourceVersion"
EventInvolvedFieldPath = "involvedObject.fieldPath"
)
type clientFieldNameToAPIVersionFieldName map[string]string
func (c clientFieldNameToAPIVersionFieldName) filterField(field, value string) (newField, newValue string, err error) {
newFieldName, ok := c[field]
if !ok {
return "", "", fmt.Errorf("%v - %v - no field mapping defined", field, value)
}
return newFieldName, value, nil
}
type resourceTypeToFieldMapping map[string]clientFieldNameToAPIVersionFieldName
func (r resourceTypeToFieldMapping) filterField(resourceType, field, value string) (newField, newValue string, err error) {
fMapping, ok := r[resourceType]
if !ok {
return "", "", fmt.Errorf("%v - %v - %v - no field mapping defined", resourceType, field, value)
}
return fMapping.filterField(field, value)
}
type versionToResourceToFieldMapping map[unversioned.GroupVersion]resourceTypeToFieldMapping
func (v versionToResourceToFieldMapping) filterField(groupVersion unversioned.GroupVersion, resourceType, field, value string) (newField, newValue string, err error) {
rMapping, ok := v[groupVersion]
if !ok {
glog.Warningf("Field selector: %v - %v - %v - %v: need to check if this is versioned correctly.", groupVersion, resourceType, field, value)
return field, value, nil
}
newField, newValue, err = rMapping.filterField(resourceType, field, value)
if err != nil {
// This is only a warning until we find and fix all of the client's usages.
glog.Warningf("Field selector: %v - %v - %v - %v: need to check if this is versioned correctly.", groupVersion, resourceType, field, value)
return field, value, nil
}
return newField, newValue, nil
}
var fieldMappings = versionToResourceToFieldMapping{
v1.SchemeGroupVersion: resourceTypeToFieldMapping{
"nodes": clientFieldNameToAPIVersionFieldName{
ObjectNameField: ObjectNameField,
NodeUnschedulable: NodeUnschedulable,
},
"pods": clientFieldNameToAPIVersionFieldName{
PodHost: PodHost,
PodStatus: PodStatus,
},
"secrets": clientFieldNameToAPIVersionFieldName{
SecretType: SecretType,
},
"serviceAccounts": clientFieldNameToAPIVersionFieldName{
ObjectNameField: ObjectNameField,
},
"endpoints": clientFieldNameToAPIVersionFieldName{
ObjectNameField: ObjectNameField,
},
"events": clientFieldNameToAPIVersionFieldName{
ObjectNameField: ObjectNameField,
EventReason: EventReason,
EventSource: EventSource,
EventInvolvedKind: EventInvolvedKind,
EventInvolvedNamespace: EventInvolvedNamespace,
EventInvolvedName: EventInvolvedName,
EventInvolvedUID: EventInvolvedUID,
EventInvolvedAPIVersion: EventInvolvedAPIVersion,
EventInvolvedResourceVersion: EventInvolvedResourceVersion,
EventInvolvedFieldPath: EventInvolvedFieldPath,
},
},
}
// FieldsSelectorParam adds the given selector as a query parameter with the name paramName.
func (r *Request) FieldsSelectorParam(s fields.Selector) *Request {
if r.err != nil {
return r
}
if s == nil {
return r
}
if s.Empty() {
return r
}
s2, err := s.Transform(func(field, value string) (newField, newValue string, err error) {
return fieldMappings.filterField(r.groupVersion, r.resource, field, value)
})
if err != nil {
r.err = err
return r
}
return r.setParam(unversioned.FieldSelectorQueryParam(r.groupVersion.String()), s2.String())
}
// LabelsSelectorParam adds the given selector as a query parameter
func (r *Request) LabelsSelectorParam(s labels.Selector) *Request {
if r.err != nil {
return r
}
if s == nil {
return r
}
if s.Empty() {
return r
}
return r.setParam(unversioned.LabelSelectorQueryParam(r.groupVersion.String()), s.String())
}
// UintParam creates a query parameter with the given value.
func (r *Request) UintParam(paramName string, u uint64) *Request {
if r.err != nil {
return r
}
return r.setParam(paramName, strconv.FormatUint(u, 10))
}
// Param creates a query parameter with the given string value.
func (r *Request) Param(paramName, s string) *Request {
if r.err != nil {
return r
}
return r.setParam(paramName, s)
}
// VersionedParams will take the provided object, serialize it to a map[string][]string using the
// implicit RESTClient API version and the provided object convertor, and then add those as parameters
// to the request. Use this to provide versioned query parameters from client libraries.
func (r *Request) VersionedParams(obj runtime.Object, convertor runtime.ObjectConvertor) *Request {
if r.err != nil {
return r
}
versioned, err := convertor.ConvertToVersion(obj, r.groupVersion.String())
if err != nil {
r.err = err
return r
}
params, err := queryparams.Convert(versioned)
if err != nil {
r.err = err
return r
}
for k, v := range params {
for _, value := range v {
// TODO: Move it to setParam method, once we get rid of
// FieldSelectorParam & LabelSelectorParam methods.
if k == unversioned.LabelSelectorQueryParam(r.groupVersion.String()) && value == "" {
// Don't set an empty selector for backward compatibility.
// Since there is no way to get the difference between empty
// and unspecified string, we don't set it to avoid having
// labelSelector= param in every request.
continue
}
if k == unversioned.FieldSelectorQueryParam(r.groupVersion.String()) {
if value == "" {
// Don't set an empty selector for backward compatibility.
// Since there is no way to get the difference between empty
// and unspecified string, we don't set it to avoid having
// fieldSelector= param in every request.
continue
}
// TODO: Filtering should be handled somewhere else.
selector, err := fields.ParseSelector(value)
if err != nil {
r.err = fmt.Errorf("unparsable field selector: %v", err)
return r
}
filteredSelector, err := selector.Transform(
func(field, value string) (newField, newValue string, err error) {
return fieldMappings.filterField(r.groupVersion, r.resource, field, value)
})
if err != nil {
r.err = fmt.Errorf("untransformable field selector: %v", err)
return r
}
value = filteredSelector.String()
}
r.setParam(k, value)
}
}
return r
}
func (r *Request) setParam(paramName, value string) *Request {
if specialParams.Has(paramName) {
r.err = fmt.Errorf("must set %v through the corresponding function, not directly.", paramName)
return r
}
if r.params == nil {
r.params = make(url.Values)
}
r.params[paramName] = append(r.params[paramName], value)
return r
}
func (r *Request) SetHeader(key, value string) *Request {
if r.headers == nil {
r.headers = http.Header{}
}
r.headers.Set(key, value)
return r
}
// Timeout makes the request use the given duration as a timeout. Sets the "timeout"
// parameter.
func (r *Request) Timeout(d time.Duration) *Request {
if r.err != nil {
return r
}
r.timeout = d
return r
}
// Body makes the request use obj as the body. Optional.
// If obj is a string, try to read a file of that name.
// If obj is a []byte, send it directly.
// If obj is an io.Reader, use it directly.
// If obj is a runtime.Object, marshal it correctly, and set Content-Type header.
// Otherwise, set an error.
func (r *Request) Body(obj interface{}) *Request {
if r.err != nil {
return r
}
switch t := obj.(type) {
case string:
data, err := ioutil.ReadFile(t)
if err != nil {
r.err = err
return r
}
glog.V(8).Infof("Request Body: %s", string(data))
r.body = bytes.NewBuffer(data)
case []byte:
glog.V(8).Infof("Request Body: %s", string(t))
r.body = bytes.NewBuffer(t)
case io.Reader:
r.body = t
case runtime.Object:
data, err := r.codec.Encode(t)
if err != nil {
r.err = err
return r
}
glog.V(8).Infof("Request Body: %s", string(data))
r.body = bytes.NewBuffer(data)
r.SetHeader("Content-Type", "application/json")
default:
r.err = fmt.Errorf("unknown type used for body: %+v", obj)
}
return r
}
// URL returns the current working URL.
func (r *Request) URL() *url.URL {
p := r.path
if r.namespaceSet && len(r.namespace) > 0 {
p = path.Join(p, "namespaces", r.namespace)
}
if len(r.resource) != 0 {
p = path.Join(p, strings.ToLower(r.resource))
}
// Join trims trailing slashes, so preserve r.path's trailing slash for backwards compat if nothing was changed
if len(r.resourceName) != 0 || len(r.subpath) != 0 || len(r.subresource) != 0 {
p = path.Join(p, r.resourceName, r.subresource, r.subpath)
}
finalURL := &url.URL{}
if r.baseURL != nil {
*finalURL = *r.baseURL
}
finalURL.Path = p
query := url.Values{}
for key, values := range r.params {
for _, value := range values {
query.Add(key, value)
}
}
// timeout is handled specially here.
if r.timeout != 0 {
query.Set("timeout", r.timeout.String())
}
finalURL.RawQuery = query.Encode()
return finalURL
}
// finalURLTemplate is similar to URL(), but will make all specific parameter values equal
// - instead of name or namespace, "{name}" and "{namespace}" will be used, and all query
// parameters will be reset. This creates a copy of the request so as not to change the
// underyling object. This means some useful request info (like the types of field
// selectors in use) will be lost.
// TODO: preserve field selector keys
func (r Request) finalURLTemplate() string {
if len(r.resourceName) != 0 {
r.resourceName = "{name}"
}
if r.namespaceSet && len(r.namespace) != 0 {
r.namespace = "{namespace}"
}
newParams := url.Values{}
v := []string{"{value}"}
for k := range r.params {
newParams[k] = v
}
r.params = newParams
return r.URL().String()
}
// Watch attempts to begin watching the requested location.
// Returns a watch.Interface, or an error.
func (r *Request) Watch() (watch.Interface, error) {
if r.err != nil {
return nil, r.err
}
url := r.URL().String()
req, err := http.NewRequest(r.verb, url, r.body)
if err != nil {
return nil, err
}
client := r.client
if client == nil {
client = http.DefaultClient
}
time.Sleep(r.backoffMgr.CalculateBackoff(r.URL()))
resp, err := client.Do(req)
updateURLMetrics(r, resp, err)
if r.baseURL != nil {
if err != nil {
r.backoffMgr.UpdateBackoff(r.baseURL, err, 0)
} else {
r.backoffMgr.UpdateBackoff(r.baseURL, err, resp.StatusCode)
}
}
if err != nil {
// The watch stream mechanism handles many common partial data errors, so closed
// connections can be retried in many cases.
if util.IsProbableEOF(err) {
return watch.NewEmptyWatch(), nil
}
return nil, err
}
if resp.StatusCode != http.StatusOK {
if result := r.transformResponse(resp, req); result.err != nil {
return nil, result.err
}
return nil, fmt.Errorf("for request '%+v', got status: %v", url, resp.StatusCode)
}
return watch.NewStreamWatcher(watchjson.NewDecoder(resp.Body, r.codec)), nil
}
// updateURLMetrics is a convenience function for pushing metrics.
// It also handles corner cases for incomplete/invalid request data.
func updateURLMetrics(req *Request, resp *http.Response, err error) {
url := "none"
if req.baseURL != nil {
url = req.baseURL.Host
}
// If we have an error (i.e. apiserver down) we report that as a metric label.
if err != nil {
metrics.RequestResult.WithLabelValues(err.Error(), req.verb, url).Inc()
} else {
//Metrics for failure codes
metrics.RequestResult.WithLabelValues(strconv.Itoa(resp.StatusCode), req.verb, url).Inc()
}
}
// Stream formats and executes the request, and offers streaming of the response.
// Returns io.ReadCloser which could be used for streaming of the response, or an error
// Any non-2xx http status code causes an error. If we get a non-2xx code, we try to convert the body into an APIStatus object.
// If we can, we return that as an error. Otherwise, we create an error that lists the http status and the content of the response.
func (r *Request) Stream() (io.ReadCloser, error) {
if r.err != nil {
return nil, r.err
}
url := r.URL().String()
req, err := http.NewRequest(r.verb, url, nil)
if err != nil {
return nil, err
}
client := r.client
if client == nil {
client = http.DefaultClient
}
time.Sleep(r.backoffMgr.CalculateBackoff(r.URL()))
resp, err := client.Do(req)
updateURLMetrics(r, resp, err)
if r.baseURL != nil {
if err != nil {
r.backoffMgr.UpdateBackoff(r.URL(), err, 0)
} else {
r.backoffMgr.UpdateBackoff(r.URL(), err, resp.StatusCode)
}
}
if err != nil {
return nil, err
}
switch {
case (resp.StatusCode >= 200) && (resp.StatusCode < 300):
return resp.Body, nil
default:
// ensure we close the body before returning the error
defer resp.Body.Close()
// we have a decent shot at taking the object returned, parsing it as a status object and returning a more normal error
bodyBytes, err := ioutil.ReadAll(resp.Body)
if err != nil {
return nil, fmt.Errorf("%v while accessing %v", resp.Status, url)
}
if runtimeObject, err := r.codec.Decode(bodyBytes); err == nil {
statusError := errors.FromObject(runtimeObject)
if _, ok := statusError.(errors.APIStatus); ok {
return nil, statusError
}
}
bodyText := string(bodyBytes)
return nil, fmt.Errorf("%s while accessing %v: %s", resp.Status, url, bodyText)
}
}
// request connects to the server and invokes the provided function when a server response is
// received. It handles retry behavior and up front validation of requests. It will invoke
// fn at most once. It will return an error if a problem occurred prior to connecting to the
// server - the provided function is responsible for handling server errors.
func (r *Request) request(fn func(*http.Request, *http.Response)) error {
//Metrics for total request latency
start := time.Now()
defer func() {
metrics.RequestLatency.WithLabelValues(r.verb, r.finalURLTemplate()).Observe(metrics.SinceInMicroseconds(start))
}()
if r.err != nil {
glog.V(4).Infof("Error in request: %v", r.err)
return r.err
}
// TODO: added to catch programmer errors (invoking operations with an object with an empty namespace)
if (r.verb == "GET" || r.verb == "PUT" || r.verb == "DELETE") && r.namespaceSet && len(r.resourceName) > 0 && len(r.namespace) == 0 {
return fmt.Errorf("an empty namespace may not be set when a resource name is provided")
}
if (r.verb == "POST") && r.namespaceSet && len(r.namespace) == 0 {
return fmt.Errorf("an empty namespace may not be set during creation")
}
client := r.client
if client == nil {
client = http.DefaultClient
}
// Right now we make about ten retry attempts if we get a Retry-After response.
// TODO: Change to a timeout based approach.
maxRetries := 10
retries := 0
for {
url := r.URL().String()
req, err := http.NewRequest(r.verb, url, r.body)
if err != nil {
return err
}
req.Header = r.headers
time.Sleep(r.backoffMgr.CalculateBackoff(r.URL()))
resp, err := client.Do(req)
updateURLMetrics(r, resp, err)
if err != nil {
r.backoffMgr.UpdateBackoff(r.URL(), err, 0)
} else {
r.backoffMgr.UpdateBackoff(r.URL(), err, resp.StatusCode)
}
if err != nil {
return err
}
done := func() bool {
// ensure the response body is closed before we reconnect, so that we reuse the same
// TCP connection
defer resp.Body.Close()
retries++
if seconds, wait := checkWait(resp); wait && retries < maxRetries {
glog.V(4).Infof("Got a Retry-After %s response for attempt %d to %v", seconds, retries, url)
time.Sleep(time.Duration(seconds) * time.Second)
return false
}
fn(req, resp)
return true
}()
if done {
return nil
}
}
}
// Do formats and executes the request. Returns a Result object for easy response
// processing.
//
// Error type:
// * If the request can't be constructed, or an error happened earlier while building its
// arguments: *RequestConstructionError
// * If the server responds with a status: *errors.StatusError or *errors.UnexpectedObjectError
// * http.Client.Do errors are returned directly.
func (r *Request) Do() Result {
var result Result
err := r.request(func(req *http.Request, resp *http.Response) {
result = r.transformResponse(resp, req)
})
if err != nil {
return Result{err: err}
}
return result
}
// DoRaw executes the request but does not process the response body.
func (r *Request) DoRaw() ([]byte, error) {
var result Result
err := r.request(func(req *http.Request, resp *http.Response) {
result.body, result.err = ioutil.ReadAll(resp.Body)
})
if err != nil {
return nil, err
}
return result.body, result.err
}
// transformResponse converts an API response into a structured API object
func (r *Request) transformResponse(resp *http.Response, req *http.Request) Result {
var body []byte
if resp.Body != nil {
if data, err := ioutil.ReadAll(resp.Body); err == nil {
body = data
}
}
glog.V(8).Infof("Response Body: %s", string(body))
// Did the server give us a status response?
isStatusResponse := false
var status unversioned.Status
if err := r.codec.DecodeInto(body, &status); err == nil && status.Status != "" {
isStatusResponse = true
}
switch {
case resp.StatusCode == http.StatusSwitchingProtocols:
// no-op, we've been upgraded
case resp.StatusCode < http.StatusOK || resp.StatusCode > http.StatusPartialContent:
if !isStatusResponse {
return Result{err: r.transformUnstructuredResponseError(resp, req, body)}
}
return Result{err: errors.FromObject(&status)}
}
// If the server gave us a status back, look at what it was.
success := resp.StatusCode >= http.StatusOK && resp.StatusCode <= http.StatusPartialContent
if isStatusResponse && (status.Status != unversioned.StatusSuccess && !success) {
// "Failed" requests are clearly just an error and it makes sense to return them as such.
return Result{err: errors.FromObject(&status)}
}
return Result{
body: body,
statusCode: resp.StatusCode,
codec: r.codec,
}
}
// transformUnstructuredResponseError handles an error from the server that is not in a structured form.
// It is expected to transform any response that is not recognizable as a clear server sent error from the
// K8S API using the information provided with the request. In practice, HTTP proxies and client libraries
// introduce a level of uncertainty to the responses returned by servers that in common use result in
// unexpected responses. The rough structure is:
//
// 1. Assume the server sends you something sane - JSON + well defined error objects + proper codes
// - this is the happy path
// - when you get this output, trust what the server sends
// 2. Guard against empty fields / bodies in received JSON and attempt to cull sufficient info from them to
// generate a reasonable facsimile of the original failure.
// - Be sure to use a distinct error type or flag that allows a client to distinguish between this and error 1 above
// 3. Handle true disconnect failures / completely malformed data by moving up to a more generic client error
// 4. Distinguish between various connection failures like SSL certificates, timeouts, proxy errors, unexpected
// initial contact, the presence of mismatched body contents from posted content types
// - Give these a separate distinct error type and capture as much as possible of the original message
//
// TODO: introduce transformation of generic http.Client.Do() errors that separates 4.
func (r *Request) transformUnstructuredResponseError(resp *http.Response, req *http.Request, body []byte) error {
if body == nil && resp.Body != nil {
if data, err := ioutil.ReadAll(resp.Body); err == nil {
body = data
}
}
glog.V(8).Infof("Response Body: %s", string(body))
message := "unknown"
if isTextResponse(resp) {
message = strings.TrimSpace(string(body))
}
retryAfter, _ := retryAfterSeconds(resp)
return errors.NewGenericServerResponse(resp.StatusCode, req.Method, unversioned.GroupResource{Group: r.groupVersion.Group, Resource: r.resource}, r.resourceName, message, retryAfter, true)
}
// isTextResponse returns true if the response appears to be a textual media type.
func isTextResponse(resp *http.Response) bool {
contentType := resp.Header.Get("Content-Type")
if len(contentType) == 0 {
return true
}
media, _, err := mime.ParseMediaType(contentType)
if err != nil {
return false
}
return strings.HasPrefix(media, "text/")
}
// checkWait returns true along with a number of seconds if the server instructed us to wait
// before retrying.
func checkWait(resp *http.Response) (int, bool) {
switch r := resp.StatusCode; {
// any 500 error code and 429 can trigger a wait
case r == errors.StatusTooManyRequests, r >= 500:
default:
return 0, false
}
i, ok := retryAfterSeconds(resp)
return i, ok
}
// retryAfterSeconds returns the value of the Retry-After header and true, or 0 and false if
// the header was missing or not a valid number.
func retryAfterSeconds(resp *http.Response) (int, bool) {
if h := resp.Header.Get("Retry-After"); len(h) > 0 {
if i, err := strconv.Atoi(h); err == nil {
return i, true
}
}
return 0, false
}
// Result contains the result of calling Request.Do().
type Result struct {
body []byte
err error
statusCode int
codec runtime.Codec
}
// Raw returns the raw result.
func (r Result) Raw() ([]byte, error) {
return r.body, r.err
}
// Get returns the result as an object.
func (r Result) Get() (runtime.Object, error) {
if r.err != nil {
return nil, r.err
}
return r.codec.Decode(r.body)
}
// StatusCode returns the HTTP status code of the request. (Only valid if no
// error was returned.)
func (r Result) StatusCode(statusCode *int) Result {
*statusCode = r.statusCode
return r
}
// Into stores the result into obj, if possible.
func (r Result) Into(obj runtime.Object) error {
if r.err != nil {
return r.err
}
return r.codec.DecodeInto(r.body, obj)
}
// WasCreated updates the provided bool pointer to whether the server returned
// 201 created or a different response.
func (r Result) WasCreated(wasCreated *bool) Result {
*wasCreated = r.statusCode == http.StatusCreated
return r
}
// Error returns the error executing the request, nil if no error occurred.
// See the Request.Do() comment for what errors you might get.
func (r Result) Error() error {
return r.err
}
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